Biting
by 2kitsune
Summary: Rin and Yukio get a little carried away after class one day and Rin leaves bite marks all over his younger brother, and the next day they get into a awkward situation when Bon points them out. Contains MxM. Rated M! for a reason. ONESHOT


Title: Classroom

Pairing: Rin x Yukio

Rating: M

Warning: Sexual context, Sexual activities, Mild swearing.

Disclaimer: I do not own Ao No Exorcist© or any of the characters

Yukio: 17

Rin: 18

A/N: This is past the ending of Ao No Exorcist, when both of them are fourteen, so in this story Yukio is seventeen and Rin is 18.

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Rin sighed for what felt like the millionth time in this one lesson, looking around the large classroom with his wide blue eyes; up the front his younger brother Yukio was droning on about boring stuff he had no interest in, but he had lots of interest for his brother instead.

With his face resting on his left hand, his right hand doodling idly in his own personal book that had random quotes from his friends and family, drawings, some short stories, and even a song that he wrote. His eyes travelled lazily from the doodle to his brother, and he kept them there.

His brother, of course, was standing directly at the front of the class; one arm outstretched to hold the text book he was reading from, his aqua eyes similar to Rin's flicked across each line as he read. His mouth opened to form each word and Rin watched mesmerized at the sight of Yukio's pink lips that he knew where petal soft with no chapping.

Looking back down at his doodle book Rin noticed that he had drawn Yukio's eyes to perfect detail, without his glasses, he didn't have any colours but the drawn eyes seemed to smoulder out happiness, he could feel the emotion seeping through the page; smiling to himself Rin understood what his friends had meant when they said he was "_A awesome drawer" _

A tap on his shoulder startled him, jumping a little Rin quickly turned to his right to see Sheime watching him expectantly, she in turn grinned at him and pointed towards the front; Yukio obviously wanted his attention; eyes widening Rin put on a sheepish grin and slowly turned to face the front.

His twin was standing in the exactly same point he was before, but his arms where now crossed and his aquamarine eyes where narrowed behind his black rimmed glasses; he was tapping his foot on the ground and look thoroughly pissed, Rin's grin widened and he tried to put on some of his Okumaru charm. But Yukio looked no more impressed then he did a couple of minutes ago, so it wasn't working.

"Sorry" Rin started, remembering to use his manners "What was that?" he asked, eyes widening innocently as though he had a good cause for not listening. Beside him he heard Sheime giggle nervously, but up the front Yukio adjusted his glasses further up his nose, a scowl formed on his face and he cleared his throat

"I asked" Yukio started, in an ice cold tone "If holy water and silver bullets do not work, what else can be used to kill demons?" Once finished he began tapping his foot again, an awkward silence filled the air as the younger brother obviously waited for Rin to answer. Meanwhile in the demon's mind he was scrambling for a answer, but coming up with blank.

Rin's eyes scanned the surrounding room, feeling all his fellow classmates' stares on his back, looking over his desk he tried to look at Shieme's textbook but the blonde shook her head, casually putting an arm over the book to cover it. Rin sighed and looked down at his feet, eyes falling onto his sword _'Wait' _Rin thought, _'My sword can kill demons' _

A smirk fell onto his lips and he looked back up, catching Yukio dead in the eyes; pausing for a general effect Rin confidently replied

"My sword, Kurikara"

The room went silent for a couple of seconds, and Rin swore he actually saw Yukio's drop open just a little; behind him he heard Izumo sigh and Shima laugh a little, Bon's voice sounded but it was too quiet for the demon to actually hear what he said, and beside him Shieme was giggling again.

"Even though that is an correct answer" Yukio started, a large grin started to spout on Rin's face "Not everyone can use Kurikara, so I'm sorry Rin but that is a incorrect answer"

"What!?" Rin demanded, frowning now "But, you can use Kurikara" he stated, immediately seeing Yukio roll his eyes even though Rin could see him blushing a little, that was un-natural but somehow cute on Yukio's face.

"But that's just you and I that can, it's an incorrect answer" Yukio said in a firm voice, almost daring Rin to argue; or course he didn't have to dare, Rin was going to do that anyway.

"But, Mephisto and Amaimon can use Kurikara too" Rin smirked a little at his answer, sure that Yukio would have no way to deny that it was a right answer; but he had to remember that Yukio was a teacher and knew better than him.

"That may be right" Yukio started, glasses flashing dangerously as he pushed them up his nose yet again "But the people you have listed are all demons who are able to use Kurikara simply because of that. I'm talking about normal human beings, Rin; and they _cannot _use Kurikara" he finished, snapping his book closed for effect.

Rin slumped back into his seat, letting out a sigh of defeat, at least he Yukio had admitted that he had gotten part of the question right, if not all; letting a lazy grin fall back into place Rin let his attention fall back onto his notebook, for some reason the eyes he had drawn where now setting him on edge and he closed his notebook with a small _snap_

Looking back around Rin's gaze fell onto the clock hanging above the blackboard, if he was reading it correctly then it read 1:10pm and lunch started at half past; sighing Rin decided to close his eyes for a small nap, eyelids closed over ice blue eyes and you could actually see the demon's black eyelashes fluttering over his high cheeks. In the background Yukio's low voice lulled him into a half dream state.

It felt like he had barely fallen asleep when the bell suddenly rang, making Rin wake up far too fast and jump about a metre in the air; beside him Shieme giggled again before turning to face the older Okumaru twin who was busy yawning and rubbing the sleep out of his eyes.

"Rin, Can I sit with you again?" she asked, far to politely again; Rin had told her again and again to stop being so formal seeing as they were friends, Shieme was getting better but was sometimes still too formal than Rin would like. The other thing is that he had been planning to sit with Bon and Shima, maybe they wouldn't mind if Shieme sat with them; the problem was, was that most of their conversations where about who was the hottest girl in class, and who they would have sex with, his friends still didn't know he was gay, and with his own brother and all.

"Sure, Shieme; but Shima and Bon will be there too" Rin answered, turning around and packing away his text book in his dark blue canvas bag which was on the ground next to his feet, behind him Rin could hear Shieme doing the same as she hummed something.

Books packed away Rin stood up, walking around to stand around the front of the desk as he waited for Shieme to finish fiddling around with her bag, thankfully she was finished packing away her books and turned to face Rin, her bag already on her back and a large smile in place. Motioning to her Rin started towards the door, Shieme beside him but not talking, he was about to slid open when Yukio's voice stopped him in his tracks

"Rin Okumaru, please stay after class"

Rin turned to look at his brother with big, pleading eyes; but all he was met with was the cold stare of his younger brother; letting out a long sigh Rin muttered "_Fine" _stepping around Shieme and moving to lean against the wall beside the door, throwing his bag to rest in front of the front desks.

Still standing right in front of the door Shieme looked towards Rin questionably as if she was asking if she could leave, without really understanding why she was asking Rin nodded a little and Shieme nodded back before opening the sliding door, stepping out into the long corridor, and closing the door behind herself; leaving the two brothers alone, finally.

"So, why did you want me to stay behind?" Rin asked, he was curious towards Yukio's actions, he couldn't remember doing anything wrong in class; apart from trying to prove the gun wielder wrong about being able to use Kurikara to kill demons, which he was still sure he had right.

"I'm disappointed at your lack of attention in class, Rin; how many times have I told you you're not allowed to draw in that book in class?" Yukio asked, Rin looked up and met his baby brothers eye; Yukio was sitting on his desk, his legs hung over the side, his arms folded over his thin chest covered by the school's white top, cardigan, and that damned black coat he always wore.

Meanwhile Rin was counting up in his head, if he was correct then Yukio had told him exactly 43 times; but other teachers had also told him off.

"43 times, exactly" Rin put on a smile and brought a leg up to bend, his foot resting against the wall and his arms crossing over his chest as he studied his younger twin, noticing how firm his expression was and how his eyes seemed to be glinting from behind his glasses

"That's not the point, Rin" Yukio said in a tight lipped tone, "The point is that you blatantly disobey me and quite frankly it's getting on my nerves"

"Not this again" Rin cut in, pushing off the wall and coming to stand in front of his younger twin, pleased to see that he was still taller than him, "I'm so sick of you pretending like a adult who can boss me around" here the demon stepped a little closer and poked Yukio's chest with his finger, "When you are younger than me" Rin continued to poke his twins chest, ignoring his brothers unimpressed glares.

"Yes" Yukio agreed, "But in case you haven't noticed I'm the mature one here, meaning that I can boss you around" Rin watched as his 'sensei' went to sit on the desk, which was weird because Yukio didn't seem like the type to do that.

"Who says?" Rin asked, fixing his brother with a devilish look; "I'd say that I'm most mature, I've done a lot more than you!" without realizing it he had moved to stand between his brother's legs, trapping him in, their bodies barely inches apart and their faces a whole lot closer.

"Just because you've done more, doesn't mean you know more" Yukoi whispered, his eyes half lidded; in that split second the two brother's seemed to realize how close they are, but didn't make any actions to move away.

Rin was the first to move, leaning in that little bit closer he tilted his head and looked up through his lashes to read his brother's expression; not seeing anything as to say that Yukio didn't want this, Rin leaned in that final bit and locked their lips together.

Blood boiled under Yukio's skin and he gasped, his hands coming up and lock behind Rin's neck; The demon smirked against his brother lips and pressed back, sneaking his tongue out to lick Yukio's lips.

As they were kissing Rin's hands trailed down his brother's sides, trailing over Yukio's ass before squeezing and smiling again when his brother let out the most delectable gasp; gently Rin pulled his brother closer on the desk, instantly the gun wielder pressed their bodies together and ground against him.

"Sh-shit, Yukio" Rin gasped, pushing back a little he stopped kissing his brother, then leaning down and beginning to nibble and then _bite_ at Yukio's ivory neck, his hands slowly undoing the gun wielder's shirt so he could bite down to Yukio's collarbones; leaving behind large, angry looking, bite marks that dibbled a little blood and it must be something to do with that they were both demons because Yukio didn't mind at all.

In fact he enjoyed it, far to much.

"Brother" Yukio moaned, lolling his head back and whimpering; Rin just couldn't get enough of the sounds his brother was letting out, deciding to take it up a step one of his hands came down to rest right on top of Yukio's member.

Instantly the gun wielder let out a loud moan, body pitching forward and folding into itself; Rin took notice of how hard his brother's breathing was and his eyes widened as a smirk covered his lips.

"Yuki" Rin growled, keen eyes noticing his brother's body shaking, "Are you a virgin?" he whispered; he had never really thought about it before, but now he realized he really should have payed more attention.

Without answering Yukio nodded, body still trembling as Rin rubbed his hand over his brother's crotch teasingly.

"Have you ever touched yourself?" Rin asked without missing a beat; he watched intently as his brother ducked his head and turned pink, and refused to look the demon in the eye.

And then too Rin's amazement, he shook his head.

"What?" Rin whispered in amazement, "You haven't?" once again Yukio shook his head; Rin 'Tsked' and stepped back from his brother, his hand's undoing Yukio's zipper before moving back even further.

Yukio actually whimpered a little and looked up with a confused expression, "Touch yourself" Rin commanded, almost laughing at his brother's expression.

"R-Rin, no!" Yukio hissed, almost looking pleading, "I can't" he whispered, defeated, and ducked his head.

"Yes you can" Rin urged in a soothing tone, "How about this" he haggled, seeing his brother's obvious discomfort, "I'll do it at the same time"

Grabbing the wheelie chair from the desk Rin sat down, bringing his legs up to his chest Rin placed his feet on either side of the chair seat and opened his legs wide; feeling his brother's eyes on him Rin smirked and reached down to grab the growing bulge in his pants, gently rubbing it against his palm and moaning.

Motioning to Yukio, Rin watched eagerly as his brother hesitantly reached down placed his own hand on his crotch; instantly Yukio let out another loud moan and his body pitched forward.

Chuckling Rin figured out pretty quickly that his brother would need some help figuring out what to do; catching Yukio's eye, Rin slowly undid his school pants and exposed his blue underwear underneath, a wet patch where the head of his manhood would be.

Yukio took in a deep breath and, shakily, undid his own zipper; exposing red underwear which also had a wet stain at the front, something that Rin took great pleasure in noticing.

Taking it up the next step Rin stuck his thumb into his underwear, hooking it around his nail and pulling them low enough for Yukio too see the base of his member; noticing how wide Yukio's eyes were Rin smirked and pulled them completely down, exposing his member to his brother.

Looking up Rin noticed how Yukio was completely frozen, his eyes wide and fixed; clucking his tongue the other brother stood up and pushed the chair away, climbing onto the desk and pulling Yukio onto his lap.

"Don't worry" Rin whispered, seeing as Yukio was on his lap he could feel how tense his brother was, "I'm not going to hurt you"

Yukio let out a little whimper but nodded, Rin made sure that his brother's realized what he was doing as he spat on his hand; then pulling down the gun wielder's under wear, feeling his balls begin to ache when he realized that Yukio was just as hard as him.

Feeling Yukio's eyes on his, Rin reached down and grasped both of their member's in one hand; Yukio let out a shaky gasp and pitched forward, his head falling onto the demon's shoulder.

Smirking Rin gently began to pump the them both, his own breathing becoming shaky; the feeling of his member against Yukio's made him want to cum straight away, gasping he faintly noticed how far gone his brother already was.

Seeing as this was Yukio's first time he didn't last long, five minutes in his head suddenly lolled back, the hand's that had found their way to Rin's back dug into the black material; his face screwed up and Rin watched with awe as his brother came shouting his name, covering their hands and uniforms in sperm.

"F-fuck" Yukio whispered, completely unlike himself; his brother brought his head back down so he could look at Rin, and gave the demon a weak smile, his hips thrusting forward still as he rode out his orgasm.

"You're so hot" Rin whispered, Yukio grinned and rolled his eyes; it was then when he noticed how hard Rin still was, the demon's member still standing proud.

"Wha-What about you?" he gasped; Rin 'tsked' and gave his brother a weak smile, "Don't worry about it" the demon started, going to get off the table so he could wipe Yukio's cum off his hand and uniform.

"No" Yukio stopped him, placing a hand on his shoulder; Rin look at his brother questionably, trying to figure out what his brother was thinking, "I mean, No, I want to help"

"Yuki" Rin smiled, "You don't have to, I can do it, I don't want you to feel uncomfortable" then realizing that, that was basically what he had just done and turned bright red.

"I want to" Yukio shot, grabbing his brother forcefully, "I mean" he stammered, pushing his fingers together and turning pink, "I want to, after you just helped me"

Rin simply nodded and sat back on the desk, his legs over the side; his eyes did not once leave Yukio as he silently got off the desk, standing in front of Rin and placing a hesitant kiss on the demon's lips.

Seeming to gain a little more confidence, Yukio actually smirked before slowly lowering himself to the ground and settled on his knees; Rin's eyes widened when he realized what his brother was going to do, smiling he leant back onto his elbows and closed his eyes.

First it was a hesitant lick at the top of his member, smearing pre-cum around its head; Rin moaned low in his throat and lolled his head back, his fingernails digging into the palm of his hand.

Then the tongue was back, licking up the whole length of his member; "F-fuck, Yuki" Rin moaned and his brother finally wrapped his hot little mouth around his member and bobbed his head.

"Ah!" Rin gasped, one of his hands falling on top of Yukio's head and pushing him down a little roughly as his other arm kept him propped up; the demon faintly wondered if he was being to forceful but Yukio didn't mean to mind as he bobbed his head up and down, every time he was able to take Rin in a little further.

Rin fell into silence as his brother sucked him off, soft moans and grunts escaping his lips as he watched Yukio's pretty pink lips wrapped around his member, leaning back onto his elbow put continuing to push down on Yuki's head; It had been so long since anything else but his hand had pleasured him, and he could already feel his stomach tightening.

Yukio's tongue suddenly flicked over the top of his member, making Rin jolt up and bend over himself "Fuck!" he swore huskily "Do that again" he ordered and took immense pleasure in the fact that Yukio immediately complied, running his tongue over Rin's slit over and over again till Rin was so sensitive he bucked up at every touch.

When Yukio came up a thin string of salvia connected his lips and Rin's member, shooting the elder a look he brought a hand off of Rin's knee and used it to slowly jack the elder off as he wrapped his mouth back around the head of Rin's member; The pleasure was too much and Rin knew that he would cum soon, his whole body prickling with sweat as he arched off of the desk and his stomach tightening till it felt like he was close.

"You close, Rin?" Yukio paused slightly to ask before going back to what he was doing, jacking Rin off faster now and lightly using his teeth with his tongue to hit the all sensitive vein under the head of his member, his ice blue eyes locked on Rin's "You gonna cum~?" he asked completely unlike himself.

"Y-yes" Rin gasped and threw his head back, his body not being able to stay still and jumping over all the place, "Oh shit, so close!" he swore, his orgasm was getting closer and closer and Rin's voice was raising higher and higher as he gasped and moaned.

"Yukio!" he yelled and came in his brother's mouth, looking down in time just too see his seed spurt into Yuki's warm mouth before his vision was overwhelmed by white and he bucked up into the air; his breathing turning to gasps as his body rolled and pitched as he rode out his orgasm "Fuck" he whispered again when he could finally open his eyes.

And when he looked down Yukio was there grinning up at him, his mouth slightly open to show Rin that his cum was still there, and with slow and deliberate movement's he swallowed it all. At the sight Rin groaned huskily and grinned toothily at his younger brother, showing his sharpened canines.

With fast movement's Rin grabbed Yukio's collar and yanked him up to his height before engaging him in a rough kiss that bruised their lips, the older brother immediately delving past Yuki's and wrapping their tongues together; faintly tasting coffee and his own cum "ah-" Rin heard Yukio moan and smirked against his younger brother's lips.

"We probably shouldn't tell anyone about this" Rin said and smirked when they broke apart "Well, we can if you want, but I doubt anyone will be okay with it seeing as we're brothers" he added but couldn't help but leaning back in and leaving more bite marks down his younger brother's chest, Yukio's moans shooting straight down his spine.

"Y-yeah, I agree" Yukio moaned and let Rin leave hickies and bites down his neck and chest "But-"he started and finally took charge by pushing Rin back, trying not to laugh at the look that his elder brother shot him "You have class, so get going" and Rin was about to protests when he heard the end of lunch bell ring.

Sighing and rolling his eyes Rin kissed his twin once more time before tucking himself back into his underwear, zipping himself up as he hopped off the desk and grabbed Kurikara "I guess I better go" he teased then and placed a teasing kiss on Yukio's lips "Unless you want me to stay~" he trailed off, sounding hopeful.

"Hmm, tempting" Yukio muttered and kissed him back for a second, losing himself in his brother "But I have class too" he murmured against Rin's lips and pushed him away.

"Fine" Rin muttered dejectedly and started making his way towards the door, swaying his hips in a way he knew work and just as he opened the door to leave he turned back to Yukio and said with great exaggeration "I'll see you back in the dorms" before leaving.

The next day Rin was back in Yukio's class and was once again falling asleep, but this time it was different because instead of Yuki telling him off the two just shot each other knowing looks when everyone else was writing stuff down; and it was all going well too, until Shieme put her hand up.

"Yes, Sheime?" Yukio called and nodded towards her to let her know she could speak, going to stand behind his desk and leaning slightly over it.

"Ah, Sensei" Sheime started and blushed, twiddling her fingers, "I was just wondering- uhm, how did you get those bite marks on your neck? They look like demon bite marks" she asked quietly, but as soon as she finished both brothers froze as everyone's attention turned to Yukio.

"Ah, no, no, they aren't demon bites" Yukio started and cursed inwardly along with the bite marks from yesterday in the classroom Rin also bit him some more last night, leaving his neck angry looking and red; Yukio had completely forgotten about them after his third class and had taken off his large coat, leaving him in his white collared shirt that while it covered the bite marks that trailed underneath his collarbones and down his stomach, didn't cover the ones peeping just over the collar and partly around the junction of his neck seeing as he had his top button undone.

"Then what're they from?" Bon called from the back of his class, and Rin sunk lower in his seat when Yukio shot him an icy look.

"Uh- they're spider bites, a spider got into my bed last night and bit me" Yukio lied and shrugged his shoulders, but he wasn't fooling anyone because his gaze was firmly placed in the middle of the class and refusing to look at any of his students.

'_You idiot Yukio!' _Rin thought _'Spider bites, really!? You might as well just tell them what really happened!'_ letting out a frustrated sigh Rin threw his hand up and didn't wait for Yukio to pick him "Yuki, can we go back to the lesson?" he called "The thing about the different types of holy water" he rattled off, trying to sound professional even though he hadn't been paying attention to the lesson.

"They look like demon bites" Shima called, ignoring Rin as he leaned back in his chair and played with his prayer beads on the desk "But from a lower level demon" he added and nod his head, and somehow everyone missed it when Rin blushed pink and cleared his throat, running a hand around his collar and exposing more bites for a brief second further down his chest.

"Y-yes, that was it" Yukio stuttered before clearing his throat once again and shooting Rin a pleading look that screamed _"DO SOMETHING!"_ but Rin simply ducked and hid his face, it would be mortifying to be found out.

"But lower level demons don't usually bite that much" Izumo spoke up in a professional voice, crossing his arms over her chest "And the only other demon the teeth marks could match would be-"here everyone stopped when they realized what the purple haired teen was going to say, and whipped their heads down to stare at the elder demon who was trying to hide his face "-Rins" she trailed off, blinking and turning red when she also realized what that meant.

"Who're you calling a lower level demon!?" Rin yelled and then turned bright red when he realised he had just confirmed every ones suspicions, "I mean-" he tried to start and gave up before thumping his head down on the desk.

"No. Way" Shima said astounded, eyes wide as he stared down at Rin who just turned more and more red.

"What's the bet that Rin's really the bottom?" Bon sneered laughing raucously and doubling over himself, clutching at his stomach.

"Well- Obviously Yukio's the bottom, he's the one with all the bites" Izumo shot in rudely, giggling to herself.

Everyone was still too much in shock to say anything, and up the front Yukio was bright red and staring determinedly down at his desk while Rin stared sheepishly up into the corner of the classroom, "Ah-" Yukio started "So, as I was saying-"

"Gee professor" Bon spoke up, smirking as he leant back in his seat "You must be into some kinky shit if you let Rin bite you that much"

"Do you think they're fucking-"Shima added in a stage whisper.

"Yukio would never do that!" Sheime suddenly said in a high pitched voice, her whole face bright red "He's- and Rin, they're brothers! They wouldn't!"

"So?" Izumo spoke up again "Honestly Sheime, you're way too innocent for you own good"

"I don't think it's gross" Bon spoke up and smirked, "It's just fucking funny, who knew Rin would be able to do something like _that_" he smirked, shooting Rin a evil look.

"Shut up, Bon" Rin snarled and turned to glare at him, "You have no idea what happened, so shut your big mouth!" he yelled, eyes flashing.

"Oh-ho" Bon laughed and turned to smile at Shima for back up, "Little demon boy is getting angry, why don't you go _bite _something" he finished and grinned toothily when Shima started laughing, Bon quickly joining in, even Izumo giggled to herself and sheime dealt with it by fainting.

But through all of this Yukio's grip on his teachers desk had just gotten tighter and tighter, and his mood had just gotten worse and worse as everyone joined in till finally had enough "Everyone be quiet!" he yelled and thumped his hands on the desk making everyone jump and sit up straighter, even Rin.

"It is _no one's _buisness what Rin and I may or _may not _do in our private lives, so if everyone would please stop prying into something that isn't your buisness and pay attention to my lesson! Because if you don't then I _will _fail you in the class"

Everyone was too shocked to speak, even Bon, and slowly opened their textbooks to pretend to read "Thank you" Yukio said politely and turned back to the board "Now, as I was saying, there are many different levels holy water to deal with the different levels of demon; as an example if you were dealing with a level three demon, you would use level three holy water, any lower level then that wouldn't work and you would have to use double, or any more than that then not only are you wasting holy water but it can also splash back onto your familiars and hurt them"

There was a huge scurry of pens on paper, and through the noise Yukio added "Oh, and Rin, I'd like to speak to you _after class_" before turning back to the board.

* * *

So I re posted this because I wanted to add some more lines :)

As I said before please REVIEW, REVIEW, REVIEW It is greatly appreciated and helps me post new stories sooner.

Oh, and to the staff who commented on this story first, yeah, I'll post whatever I want even if it is M! Rated. Lot's of peoples stories are left alone and I don't appreciate getting a warning on my stories where all my other ones are left alone. Thank you :)


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